Telephone system



Jan. 9, 1934. F. KESSLER ET AL TELEPHONE SYSTEM Original Filed Dec. 5, 1929 9 Sheets-Sheet l Inventors Frank Kassie: Her-BET? ETEILEH E2 E5 .Ta k 52:11.11 Ell DH I Jan. 9, 1934. F. KESSLER ET AL TELEPHONE SYSTEM Original Filed Dec. 5, 1929 9 Sheets-Sheet 2 Fan E55 Hal-12w SE12 Inuen are F k J ck Ecummru Jan. 9, 1934- F K SS E ET AL TELEPHONE SYSTEM Original Filed Dec. 5, 1929 9 Sheets-Sheet 3 Inusnfurs Frank Kessler" Hal-"EFT 515121 DE as Jack Ecmmcrm Jan. 9, 1934. KESSLER ET AL 1,942,651

TELEPHONE SYSTEM Original Filed Dec. 5, 1929 9 Sheets-Sheet 4 'InuEntnr- E- Frank KEEEILEI Herb Q Y 515% pages Jack Ecumcru'fi' Jan. 9, 1934. F, KESSLER ET AL 1,942,651

TELEPHONE SYSTEM Original Filed Dec. 5, 1929 9 Sheets-Sheet 5 -Inuantl:zrs

Frank Kassler Her-EFT 5% D E 1 Es Jack Ecmmcrcflt Jan. 9, 1934. F. KESSLER ET AL TELEPHONE SYSTEM Original Filed Dec. 5, 1929 9 Sheets-Sheet 6 Inuan Dr"; Frank X25512? Hal-her EFL la @5525 Jack Ecnmcr'fijt a?! 5 E1113.

34- F. KESSLER El AL 1,942,651

TELEPHONE SYSTEM Original Filed Dec. 1929 9 Sheets-Sheet 7 Inventors Frank KEEBIEF Herbert SEE @125 Jack ECUUJEFUjt Jan. 9, 1934. F KESSLER ET AL 1,942,651

TELEPHONE SYSTEM Original Filed Dec. 5, 1929 9 Sheets-Sheet 8 SSDM dral} T Fran sealer Her-BET SEE 1] age 5 Ja: Ema-511' FTE.

Jan. 9, 1934. F. KESSLER ET AL TELEPHONE SYSTEM Original Filed Dec. 5, 1929 9 Sheets-Sheet 9 vii w x m =5 22 @N. zoo

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Inuen urs H granlglesslilr E E E E5 J LR E G uTTJT Patented Jan. 9, 1934 UNITED STATES 1,942,651 TELEPHONE SYSTEM Frank Kessler and Herbert Stanley Deyes,

Liverpool, and Jack Scowcroft, Bolton, England, assignors' to Associated Telephone and Telegraph Company, tion of Delaware Application December 5, 1929, Serial No. and in Great Britain December 7,

Chicago, 111., a corporanewed October 26, 1931 61 Claims.

The present invention relates to telephone systems and is more particularly concerned with multi-exchange systems comprising a number of exchanges of small capacity. Considerable difficulty has been experienced in devising economical arrangements for providing automatic service to a network of exchanges which are widely separated and which each comprise only a small number of lines, for instance 20 or 30, as may well occur in rural districts. It is the chief object of the present invention to provide an improved arrangement for giving service in these circumstances with the minimum of equipment and great economy in the number of trunk lines required.

In order to enable the trunking arrangement to be as flexible as possible, the system according to the invention cintemplates the use of register translators which will respond to the initial digits of the exchange name, for instance,

the first two, and translate these digits into a routing number which can be chosen to permit the most eiiicient trunking arrangements and which can subsequently be altered if desired without affecting the subscribers numbers. Equipment of this nature is, however, costly, and owing to the small size of the exchanges of the type considered it would need to be provided in such quantities as to be uneconomical if translating equipment were located at each exchange. According to the invention, therefore, the translating equipment is centralized at an exchange in the network which is most suitably placed geographically in relation to the other exchanges and a number of exchanges employ this translating equipment in common.

According to another feature of the invention the translating and so-called tandem equipment is made up int) a separate unit, which is kept distinct from the local switching equipment in that exchange, whereby the local equipment may be the same in all exchanges and it is only necessary to add the tandem equipment in the exchange which by virtue of its size and position is most suited to receive it.

According to a still further feature of the invention, metering arrangements are provided in which the meter is operated singly or a number of times for each call or period of time elapsing during the progress of the call, depending on the zone in which the called subscribers exchange is situated. A further feature of the invention concerns a 25 point rotary switch, functioning as an outlet selecting switch which is operated by a single series of impulses sent out by the register translator.

The invention will be better understood from the following description of the circuit arrangements, reference being made to the accompanying drawings comprising Figs. 1 to 9 which should be arranged as follows: Fig. 2 should be placed to the right of Fig. 1 and Fig. 3 to the right of Fig. 2. Figs. 4, 5 and '7 should be placed below Figs. 1, 2 and 3 respectively and Fig. 8 to the right of Fig. 7, Fig. 9 should be placed in a position below Figs. 7 and 8, while Fig. 6 should be placed below Figs. 4 and 5. The interconnecting lines will now be found to be in alignment and a complete circuit of the invention is thus obtained. This arrangement, however, is given by way of example only, since it will readily be apparent to those skilled in the art that the principles of the invention are capable of wider application and are not limited to the precise arrangement shown.

Referring now more particularly to the drawings, Fig. 1 shows a subscribers line circuit and a link circuit at the local exchange. Figs. 2 and 3 show further portions of the link circuit, whilst Fig. 3 also includes (to the right of the dotted line) metering equipment common toa number of link circuits. Fig. 4 shows the circuit of the junction extending to the tandem office; Fig. 5 shows the circuit of the tandem 1st Code Selector; Fig. 6 shows the switch employed for calls incoming over the junction, and Figs. 7, 8 and 9 show the circuit of a register translator.

A description will first be given of the establishment of a connection between a calling subscriber A whose number is 2121, and a wanted subscriber B in another automatic exchange, whose number we will assume to be 3333.

In order to simplify the tracing of the circuits through the various drawings, the following table sets out the relays which are located in each figure:

L AD SP CS SA BA DAS DR DOA 00 BD ST KA SB BB DAK DTP DAD A CD MA SC BC DDA DPR DBD B C MB SD BD DDB DS DCD K F MV SE BE DDC DSA S H MW SG BF DO DSZ M CB MX SH BG DCO DRA CA OH MY SI BH DBR DA TD SK BS V DB E SL BAD G SM BBD SEA SLA

SLB

When subscriber A removes his receiver, re-

lay L is operated over its upper winding in series with the subscriber's instrument. Thereuponat armature 12 it r moves earth from the associated wontacts in the banks of the line finder switches a such as FS so as to render the line selectable and also prepares a circuit for thecut-oil relay CO; at armature 11 it disconnects the cut-oi! relay from one of the speaking conductors and at armature l3 completes a circuit-extending over conductor 15, wiper 110 of the: distributor DA and conductor 16 for start relay S. Relay 8 thereupon operates and at armature 31 connects the magnet FDM oi the finder switch F8 to test wiper 103, at armature s2 completes a circuit for switching relay K and magnet FDM in series, at armature 33 opens a point in the circuit of relay CS and at armature s4 closes a point in a circuit over the connector test wiper 160 which will not be operative at this stage of the connection.

Since the test contacts associated with lines which are either in use or not calling are connected to earth, switching relay K is short-cireuited and magnet FDM is operated in the usual manner and rotates the wipers 101-104 of the finder switchFS until wiper 103 encounters the contact associated with the calling line. When this occurs, no further operating circuit is completed for the magnet FDM; and relay K, being no longer short-circuited, energizes in series with the magnet. Thereupon at armatures k1 and k2 it connects the wipers 101 and 102 through to the battery feed relay A, at armature k3 closes a point in the circuit of relay CS, at armature k5 removes earth from the test contact in the bank associated with the wiper 109 of the link finder switch JF and prepares a circuit for relay CH, and at armature k6 connects direct earth via armature M to test wiper 103, whence it is extended via armature 12 through the lower winding of relay L and the winding of cut-oiT relay CO to battery. Armature k6 also applies guarding earth over conductor to the bank of wiper 111 of the distributorDA whence it is extended over the interrupter contacts to the magnet DDM so that this magnet operates to advance the wipers of the distributor in search of the next idle link. Relay CO operates and at armatures col and 003 disconnects earth and the upper winding of relay L from the speaking leads but relay L remains operated over its lower winding. Relay CO also at armature co2 opens the start circuit for relay S extending over wiper 110 01' the distributor DA and at armature co4 closes a point in the circuit of the magnet of the meter MT.

When relay K energizes and extends the circuit of relay A to the line, relay A energizes and at armature a1 completes the circuit of relay B. Relay B at armature b1 provides a holding circuit for relayK, which would otherwise release when armature s2 falls away after its slow release period. Relay B also at armature b2 completes the initial circuit of metering control relay M, at armature b3 prepares a circuit for relay CA, at armature b4 prepares a circuit for the lower winding of relay ST and at armature b5 opens a point in the circuit of release magnet MRM of the switch MS. a

When relay S has de-energized a circuit is completed at armature s3 for relay CS which there upon operates and at armature cs1 connects the driving magnet JDM of the switch JF to test wiper 109 and at armature cs2 completes a circuit for relay KA and magnet JDM in series. Magnet JDM now operates to rotate the wipers the contact. from which earth has been removed by the operation 01 armature k5 whereupon relay KA is no longer shbrt-ci'rcuited and energizes, whereat at armatures M3 and ka6 the junction conductors 20 and 21 extending to the 1st code i?- selector in Fig. 5 are disconnected from conductors 23 and 24 extending to the incoming switch in'Fig. 6 and are connected to wipers 107 and 108. Moreover relay KA at armature kal closes the circuit of magnet CDM, at armature ka2 opens the circuit of relay CS, at armature kai interrupts the connection of magnet JDM to wiper 109, and at armature ka5 prepares a locking circuitior relay KA over wiper 109. Armature ka5 also extends earth over wiper 109, conductor 14 and armature 1:5 to relay CH which thereupon operates and at armature ch1 removes earth from conductor 17 and the 25th contact in the bank 111 of the distributor DA. This bank contact number 25 is multipled to all links wired to its banks so that when all links are engaged i. e. all CH relays operated, the 25th bank contact of wiper 111 will be free from earth and the distributor wipers will rest on the 25th set of contacts to save continuous hunting over engaged contacts.

Moreover relay CH on energizing, at armature ch2 opens a point in the homing circuit over wiper 159 of the switch LS, at armature ch3 transfers the circuit of relay M to armature 1 of relay DB, at armature ch4 completes a local locking circuit for itself and a locking circuit for relay KA, at armature ch5 closes a point in the test wiper circuit which is not operative at this time, at armature ch6 prepares impulsing circuits for the switches MS and LS and at armature eh? prepares the circuit of relay ST.

Relay DB is now connected in the impulse-out circuit via. armature a2, conductor 19, wiper 107 of switch JF, armature ka3, conductor 20, armatures swl and sd2 to the upper winding of relay SL and earth, relays DB and SL operate in series with each other. As relay DB operates almost at the same'moment that relay CH operates, the operating earth for relay M which was previously provided by armature b2 is now provided by armature dbl and ch3 so that meter-control relay M remains operated.

On the operation of relay SL, Fig. 5, armature s11 connects earth via the upper winding of relay SM and armature sk6 to relay SB which thereupon energizes, while armature s12 connects the windings of relays SI and SD across relay SA which operates. Armature sbl connects earth to a locking wire which is not effective at this 3 time, armature sb5 connects earth to conductor 48 and wiper 128 of switch Q and thence via conductor 53 to start relay DAS which energizes.

Armature sb8 connects up relay SLA over the impulse back conductor 21,.armature ka6, wiper 13-.- 108 of switch JF, conductor 13, conductor 7 to relay DA, so that relays DA and SLA operate in series. Armature sb9 connects earth to conductor 25 and bank contact to busy the junction against incoming calls. When impulse-receiving relay 14-. DA operates, armature dal connects earth from armature ch6 over the 1st back contact of wiper 164 of switch MS to relay CB which is thereupon energized to prepare a circuit for magnet MDM. Moreover when relay SLA is energized, earth is connected .at armature slal to the righthand winding of electro-polarized relay SD which relay however, does not operate at this time owing to the two windings producing opposing fluxes. Although earth is extended at armature 811 via the winding of marginal relay SM to relay SB,

relay SM does not operate as the current flowing through its winding is not sufllciently great.

When relays SA and SB operate as mentioned, armature sb6 connects earth via armature sal and wiper 121 to relay SC which operates. Armature so? thereupon removes'earth from conductor 43, which connects with bank 126 of switch R, and substitutes the winding of relay SK. When start relay DAS operates as already mentioned, armature das2 connects the magnet RDM via its interrupter springs and relay DAK in series. The wipers 122127 of switch R now rotate in known manner until test wiper 126 reaches the contact associated with the calling 1st code selector, which contact is free from earth; relay DAK will now be relieved of its short-circuit and will energize. When DAK energizes, it opens the test circuit at armature dakl; connects up wipers 122, 123, 125, and 127 at armatures dak5, dak7, dakfi and dak8; and at armature dak2 extends earth over armature das2 to wiper 126, conductor 43, armature s07 to relay SK which energizes.

When relay SK energizes, armatures sk3 and sk4 switch the holding circuit of relay SA to the loop across wipers 124 and 125; armature skl closes a holding circuit for relay SB through armature sbl, while armature sk6 disconnects the initial energizing potential from relay SB and extends it by way of conductor 47, wiper 127, and armature dak8 to impulse-receiving relay DDA of the register sender, placing relay DDA under the control of line relay SL; and armature sk5 disconnects the impulse-back conductor 21 from battery by way of relay SLA and extends it to battery in the register translator, by way of conductor 34, wiper 123, armatures dale! and dcl, and the associated resistance element. Relay SLA falls back, but the impulse-receiving relay DA in the originating exchange remains operated over the new circuit.

In the register translator, impulse-receiving relay DDA now operates andat armature ddal completes the circuit of release relay DDB which is energized, and the auxiliary release relay DBR is also energized from earth at armature ddbl.

The register translator represented by Figs. 7, 8 and 9 is now associated with the 1st code selector shown in Fig. 5. 3

Relay DBR at armature dbr3 closes the circuit of the vibrator DV and at armature (Z1218 extends dialing tone over conductor 170 via wiper 144, wiper 124, conductor 41, armature sk4, armature shl, armature s03 and condenser to the speaking conductor of the 1st code selector, whence it is transmitted over the junction to the calling party as an indication that he may proceed to dial the digits of the number he requires.

When the calling subscribers calling device is operated to generate the series of impulses corresponding to the first digit (3), relay A is released and re-operated according to the number of impulses transmitted. Armature a1 now vibrates and energizes relay CA which maintains relay DB operated at armature cal, and at armature ca2 connects battery via a low resistance in parallel with supervisory relay DB to improve the quality of the pulses sent to the tandem oiiice; armature a2 opens and closes the circuit of relay SL in the 1st code selector and armature sll is vibrated in synchronism with the dialled impulses. Armature sZl opens and closes the circuit of relay DDA and this relay now transmits, at armature ddal, earth pulses via armature dbr6 to relay DDC, and via wiper 145 and conductor 54 to the two-step counting relays DAD, DBD, and DCD, and to change-over relay DCA. Relay DCA operates responsive to the first impulse and remains operated until the impulses cease. The first impulse passes through armatures dad2, dbd2, dcd2, dbd3 and dadB to the upper winding of relay DAD. Relay DAD is of the two-step type, the first earth impulse received operates armature dadl only; when the earth is removed, relay DAD operates fully via its two windings in series over conductor 55, conductor 50, armature dbr3 to earth, and at armature dad3 switches the pulsing wire to relay DBD which will operate in a similar manner to relay DAD when the second earth impulse is received. When relay DBD operates fully, armature dbd4 releases relay DAD, and armature dbd3 switches the pulsing circuit over to relay DCD. When relay DCD operates fully at the end of the third impulse, it will connect earth via armature dcd5 to the bank and wiper 130 and magnet CDM which will rotate its wipers 130-137 to the tenth contacts; relay DCA which energizes through its lower winding during pulsing remains energized during automatic rotation of the switch wipers via its upper winding in parallel with the magnet CDM.

At the end of the wiper rotation, relay DCA releases and, the second train of impulses will traverse a new circuit over armature dcd2, armature deal and armature (10112 to magnet CDM which will step its wipers three steps in accordance with the second digit (3) of the called partys number.

Relay,DDC which operates with each series of impulses connects earth via armature ddcl to period after relay DDC de-energizes. It follows, therefore, that magnet DDDM of the inputcontrol switch will receive an energizing current which will step its wipers 145, 146 and 147 one step at the end of each series of impulses. When the third series of impulses is received, it follows therefore that wiper 145 will be resting on the third contact and the earth pulses of the third digit (3) will be extended to magnet NAM which will advance its wipers 148 and 149 three steps. The fourth digit (3) will find wiper 145 on the fourth contact and magnet NBM will step its wipers 150, 151 and 152 three steps. As the called partys number consists of four digits only, the full complement of impulses has now been received.

To return to the point where the first and second digits have operated the magnet CDM and its wipers; at the end of the reception of the second digit the wiper 147 is on the second contact and the following circuit for start relay DPR is completed: earth at armature dbr3, conductor 50, wiper 147 and bank contact number 2, bank contact 1 and wiper 142 to relay DPR. When start relay DPR energizes, armature dprl opens a point in the circuit of the vibrator DV which releases its armatures. The design of the vibrator is such that when its armature is released magnetically, it vibrates a number of times before coming to rest, due to its own momentum and the design of its restoring spring, in such a manner that armatures dvl and (1112 are opened and closed for the purpose of providing impulses to the circuit to be described.

It should be mentioned at this point that when the register translator is taken into use, armature dbr2 completes a circuit over wiper 143, for relay DC which energizes. When relay DC energizes, armatures dcl to 1204 disconnect the sending circuit, including armature dvi, from the loop through wipers 124 and 125 and connect it in the impulse-back clrcuit,,which includes wiper 123 and extends to relay DA by way of junction conductor 21 and conductor 24. In performing this operation, armature dcl opens the normal circuit over wiper 123, and armaturedc3 closes a holding circuit overwipers 124 and 125.

On the first interruption of armature dvl, the circuit over impulse-back conductor 34 is opened and relay DA deenergizes and at armature dal completes the circuit to magnet MDM which advances its wipers one step. Armature dv2 will complete the circuit: earth, armature dbr3, conductor 50, wiper 47 and bank, armature d322, armature dv2, winding of magnet SSDM to battery. Magnet SSDM steps its wipers 138 and 139 one step so that they make contact with the second set of contacts. This series of operations will continue, i. e. pulsing of magnets MZDM and SSDM until wiper 138 of switch SSDM finds earth on one of its bank contacts. The translation ararmature dvl and opens the circuit over vibratorarmature dv2 at armature dsz2; at armature dsz3 the vibrator is re-energized in readiness for the next series of impulses.

Magnet MDM, having been stepped in synchronism with magnet SSDM, will have advanced its wipers three steps.

Relay DSA operates when wiper 39 of switch SSDM is stepped from its home position and armature dsa2 now extends earth over conductor 50 via armature dszl to the winding of relay DSZ to provide a temporary holding circuit; armature dsal completes the circuit of magnet CSDM which energizes. Moreover armature dsz5 extends the earth which is operating DSA via the interrupter springs to magnet SSDM which rotates its wipers until the first contact "home position is reached whereupon wiper 139 fails to find earth and magnet SSDM stops operating.

Relay DSA also de-energizes after a pause period and at armature dsa2 opens the holding circuit of relay DSZ which also de-energizes, while at armature dsal relay DSA opens a point in the circuit of magnet CSDM which advances its wipers 140-144 one step. Moreover, wiper 143 opens the circuit of relay DC which de-energizes and at armatures dc1-dc4 recloses the holding circuit over wiper 123; opens the local holding circuit over wipers 124 and 125; and transfers wipers 124 and 125 back to the sending circuit in place of wiper 123.

Armature dsz3 opens a point in the circuit of vibrator DV which again releases its armatures. Armature dvl opens a point in the circuit of relay SA which de-energizes and at armature sal completes the circuit of relay SEA and magnet SDM in series both of which are energized. Magnet SSDM energizes over armature c102 and steps its wipers 138 and 139 seven steps whereupon wiper 138 finds earth to energize relay DSZ. At this time magnet SDM has also advanced its wipers 116-121 seven steps, 1. e. to the eighth set of contacts. Relay SE energizes in a circuit extending from earth over armatures sb4 and 302 and over bank and wiper 120. Relay SE at armature sel closes a locking circuit for itself over the interrupter springs of magnet SDM and armature sb4 which -is independent oi armature 802. Moreover when relay 8C releases at the end of the first'series of impulses, armature sc2closes a point in a further circuit for relay SEA. Relay SEA is now provided with another holding circuit andmagnet SDM is energized. Relay SEA being slow to release does not de-energize when relay SC releases. The interrupter springs of magnet SDM discrnnect the circuit of relay SE which, in turn at armature se2 opens a point in the circuit of magnet SDM. The wipers 116-121 of switch SDM are now advanced one step, i. e. to the 9th set of contacts.

From this point the subsequent rotation of the SDM switch wipers depends upon the presence of a disengaged trunk to a switch next in the train. In the example shown in the drawings there are three outlets to switches ahead; the bank contacts of wipers 118 and 119 associated'with the first two lines are strapped to cause automatic rotation of the switch when the outlets are engaged; the last outlet (No. 3) has the bank of wiper 119 only wired in order to give busy tone when outlets 1, 2 and 3 are engaged. When, therefore, wipers 116-121 reach the 9th set of contacts and the outlet is engaged, earth from the switch ahead will extend over -conductor 44, through wiper 118,- armatures s04, sm3, sh3, sh3, sm7 and sg3, interrupter springs, bank and wiper 120 to relay SE which will re-operate and atarmature se2 again completes the circuit of relay SEA and magnet SDM. Moreover when magnet SDM is energized the interrupter springs open the circuit of relay SE which releases and opens the circuit of magnet SDM; wipers 116-1'21 now step to the next set of contacts and if conductor, 45 is free from earth, indicating that the outlet to the switch ahead is free, relay SE will not re-operate and the short circuit will be removed from relay SH which will energize over the following circuit: earth, armature sb4, winding of relay SE, armatures m7 and 393, interrupter springs, bank and wiper 120 winding of relay SE to battery. Relay SE does not, however, energize in series with relay When relay SH energizes, the talking circuit is switched through to wipers 116 and 117 at armatures shl and sh2 and relay SA releases; the next series of impulses will now be transmitted to the switch next in the train over wipers 116 and 117.

When relay DSZ operates at the conclusion of sending the second digit of the translated code, the previously mentioned pause interval precedes the sending of the third digit 1 which, along with the fourth digit 0, will be transmitted over wipers 116 and 117 to succeeding switches.

At .the end of impulsing for the fourth digit, relays DSA and DSZ operate as before and operate the magnet CSDM to step its associated wipers. Now bank contact number 13 of wiper 137 is jumpered to the wire connecting with the normal position contact of armature dsa2; relay DSZ will, therefore, remain operated over the circuit: earth, armature dbr3, conductorv50, wiper 147 and bank wiper 141 and bank contact number 4, wiper 136 and bank, armature dsa2, armature ds zl, winding of relay DSZ to battery. The

switch magnet CSDM will also be energized in series with its interrupter springs, wiper 140 and bank, armature dbrl and the circuit previously described. Wipers 140 and 141 will rotate one step until wiper 141 reaches the 6th contact associated with the 'first numerical storing switch wiper 148, which, as the called partys number is 3333, will be resting on contact number 3.

At this time wiper 141 will have opened the circuit of relay DSZ which will de-energize and allow the vibrator DV to release. The previously described operation of impulsing will now continue until wiper 138 has advanced three steps when it will receive earth from wiper 141 and bank contact. After a pause sending of the final numerical digit will take place.

When the impulses of the last digit have been transmitted and the magnet CSDM has de-energized and stepped its wipers to the 8th set oi con, tacts, the earth which is connected to wiper 141 as previously mentioned will extend over bank contact 8 of wiper 141, bank contact 13 of wiper 132, conductor 49, normal contacts controlled by armature dcol, winding of relay DCO to battery. Relay DCO energizes and at armature dco5 opens a link over wiper 126 and conductor 43 to relay SK. Relay SK de-energizes and at armature skfi opens the circuit of relay DDA of the register translator which also de-energizes and in turn opens the circuit of relay DDB and consequently brings down the relays controlled therefrom, including relay DAK. Relay DAK ole-energizes and opens the circuits to wipers 122-127 and thereby releases the register translator from thefirst code selector.

When the called party answers, battery is reversed from the switch ahead to wipers 116 and 117; and polarized relay SD energizes. Relay SD at armature sd2 disconnects earth through the upper winding of relay SL and connects battery through relay SLB to conductor 20. Relay DB now de-energizes and at armature dbl opens the circuit of relay M which also de-energizes and at armature m1 closes a point in the circuit of the upper winding of start relay ST in series with relay MA which is common to a plurality of links. Relays ST and MA are energized and relay ST locks itself at armature stl by way of armatures sp4 and b4. Relay MA at armature mal closes the circuit of relay -MB; at armature ma2 closes the circuit of relay MW and at armature ma3 connects earth to the vibrator MV. Relay MW and the vibrator MV are energized, whereupon armature mwl prepares a locking circuit for relay MW, and armature mw5 closes a point in the circuit of relay MX which, being of the two-step type operates its light armature mml only. At armature mvl, earth is extended to armature mw4, conductor 31, number 3 bank contact and wiper 166,

rmature st4, conductor 11, wiper 104 and bank, armature 004 to the meter MT which operates.

Relay MB, which is slow to energize, will now attract its armatures and at armature mb2 opens the circuit of relay MA to prevent other ST relays operating after the metering operation has started, and at armature mbl locks itself up over armature st2, while at armature mb3 it supplies locking potential for relays MW, MX, MY. Moreover when relay MA de-energizes, armature ma2 opens the original energizing circuit of relay MW and armature maS opens the circuit of the vibrator MV which de-energizes and allows its armatures mvl and mv2 to complete a pendulum movement and produce a series of earth pulses,

When armature mv2 first releases, the short circuit is removed from the left-hand winding of On the return swing of the vibrator, armature mcl extends earth via 10:05 to the meter which again registers; armature mv2 extends'earth via armatures my2 and 1120.3 to the lower winding of relay MY which is also of the two-step type and operates its light armature myl only. When the vibrator again swings to normal armature mvl opens a point in the meter circuit and armature mp2 removes the short-circuit from the upper winding of relay MY which is now fully energized over its two windings in series.

The next return swing of the vibrator will close armature mvl to again complete the meter circuit via armature my3 for the third operation. At the same time, armature mvZcompletes a circuit through armature my4 for the upper winding of relay SP which will energize partially and operate its armature sp5 only. When armature mvl next releases, the meter circuit is opened and at armature 111.212 the short circuit is removed from the lower winding of relay SP which energizes fully and at armature sp'l opens the circuit of relay MY which thereupon de-energizes. The meter has now registered three times.

Moreover, when relay SP energizes fully, its armature sp3 opens the circuit of relay ST which de-energizes and at armature st4 opens a point in the meter circuit. Armature sp2 closes the time-period circuit by which magnet TDM receives earth pulses over conductor 171 at intervals of half a minute and advances its wipers 167-169 one step every half minute; armature st2 opens the locking circuit of relay MB and armatures st3 and sp3 complete the dissociation of the common equipment from the circuit.

At the end of a period of two and a half minutes, i. e. when the magnet TDM has received five impulses and advanced its wipers 167-169 five steps, wiper 169 connects a warning tone over conductor 171 to the calling party's line to inform him that the normal period of the call has expired. Moreover, if the call still persists at the end of a further half-minute period wiper 168 will advance to the 7th contact and open the circuit of relay SP which de-energizes and re-connects the common metering equipment to cause further registration on the calling partys meter.

The metering circuit might if necessary be so arranged that a units system of registration could be employed; with this method of metering the revenue would accrue on a strict time period basis with variation in the rate of charge for calls to different zones. For example, it might be arranged that a subscriber's meter should be operated once every 10 seconds during the effective period of a call to zone 1 and twice during a similar period for a call to zone 2 and so on. The circuit for this system of charging calls could be arranged by connecting conductors 31-33 to rotating camsor some other arrangement giving earth pulses at the rate of say 6 per minute for zone 1 (conductor 31) 12 per minute for zone 2 (conductor 32) and 18 per minute for zone 3 (conductor 33). The apparaus shown in Fig. 3 would not then be required and the metering wire to wiper 166 would be connected via an armature which would operate when relay CH was energized and an armature on relay M which would close a further point in the circuit when relay M was de-energized. For a call to zone 2, therefore, relay M would de-energize when the called party answered and the meter would be operated every five seconds over conductor 82 which would be connected to an impulse source supplying impulses at the rate of 12 per minute.

when the calling party restores his receiver at the conclusion of the call, relay A is de-energized and at armature a1 opens the circuit of relay B which de-energizes and at armature b1 opens the circuit of relay K which also de-energizes and at armature k6 removes the holding earth which allows relays KA and CH to deenergize. Relay K at armature k4 opens the cir cuit oi relays L and CO which de-energize. Armatures M3 and M6 open the Junction circuit to the 1st code selector and relay SLA deenergizes and at armature slal disconnects the right-hand winding of relay SD. Relay SD deenergizes and at armature sdl opens the circuit of relay SL which also de-energizes and at armature all opens a point in the circuit of relay SB. Relay SB de-energizes and at armature sb4 removes earth from the lead holding re lay SH, at armature sb2 connects earth via the interrupter, springs, bank and wiper 120 to relay SE which energizes and at armature se2 extends earth from armature 31210 to the winding of mag-' net SDM via relay SEA; magnet SDM advances its wipers 116-120 one step and the interrupter springs open the circuit of relay SE which deenergizes and again completes the circuit of magnet SDM. This sequence of operations will continue and cause the wipers to be advanced until the home position is. reached whereupon wiper 120 opens the circuit of relay SE which de-energizes and prevents further rotary motion. The .relays in the 1st code selector are now at normal and the switch may be taken from another source for further service.

To return to the point where relay KA deenergized, armature lcal removes earth from the bank of wiper 106 and allows the junction to be used by other callers, armature ka2 closes a point in the circuit of relay CS which, however, will not operate until another call takes the service of the Junction.

In the event of wiper 119 of the 1st code selector reaching the bank contacts of the last outlet in a group and finding it busy, since there is not strapping between the banks of wipers 118 and 119 in this position wiper 118 would not find earth and the stepping circuit for magnet SDM would be opened, relay SEA would release and at armature seal close a point in the circuit of relay SG which would energize from earth over bank contact of the last outlet in the group, wiper 119 and armature seal as mentioned. Relay SG at armature sgl completes a holding circuit for itself to earth at armature sbl and at armature .sg2 extends busy tone over conductor 173 via the condenser to the speaking conductor and thence over the junction to the calling party who is consequently aware that an engaged condition prevents the completion oi. his call.

Consider now the case in which the calling party dials a non-existent exchange code; in this circumstance the bank of wiper 1 33, associated with that code, is wired, along with other unused contacts, to the spare code terminal 174.

when wiper 147 of the input control switch DD steps to third position, relay DR operates and at armature dr2 connect battery via a low resistance to wiper 127 in parallel with relay DDA. As a .resultthe current flowing through the winding of relay SM increases to such a value that SM energizes and at armature sml locks up to earth at armaturesll. Relay SM at armature sm5 opens a point "in the circuit over conductor 47 to relay DDA which de-energizes and opens the circuit of relay DDB. Moreover relay DDB at armature ddbl opens the circuit of relay DBR which de-energizes and at armature dbr'l removes earth from the windings o1 relays DAK and SK.

When relays DAK and SK de-energize, the register translator is completely dissociated from the 1st code selector. At armature sm'l, relay SM opens the circuit of relay SH (in case it is closed) and places earth from armature sbl through contacts controlled by armature s93 and interrupter contacts sdm on all contacts in the bank of wiper 120 except the first and second, while armature sm8 extends this earth potential to the first contact. As a result, relay SE is operated and interacts with driving magnet SDM, as it closes its circuit at armature se2. The wipers 116-121 are driven, therefore, from any position in which they happen to be standing until they reach position two, whereupon wiper 120 completes the following circuit: earth, lower winding of relay SG, armature sm6, second bank contact and wiper 120 to relay SE. Relay SG is energized but relay SE is adjusted so that it does not energize in series with the winding 01 SG. Number unobtainable tone is connected up over conductor 175 at armature sm4 via armature $02 to condenser and speaking conductor and thence to the calling party, as an indication that the number called is not obtainable.

A further condition demanding the number unobtainable tone circuit arises when the calling subscriber, after seizing the register controller and translatoniails to dial; or, after having dialled certain digits, delays the dialling of 120 the remainder for an excessive period. Under this condition the time pulse earth is extended from conductor 176 via the supervisory equipment to the right-hand winding of relay DTP; the time pulse earth is applied for a portion of a second only; and, so long as it remains connected to lead 87, relay DTP will only operate its armature dtp2. When the time pulse earth is withdrawn, relay DTP energizes fully with both its windings in series to earth over conductor 13;) 50, and at armature dtpl prepares the circuit of relay DR. The next application of the time pulse earth energizes relay DR which at armature dr2 connects battery to wiper 127 and relay SM. The sequence of operations is the same as described under the previous example.

A further illustration will now be given dealing with a call from subscriber A whose number is 2121 to a second subscriber in the same satellite oifice whose number will be assumed to be 2129. 14 When the calling subscriber removes his receiver to originate the call, the sequence of operations previously described takes place and the call is extended to the register translator in the tandem oiiice. Relays DDA, DDB, DBR and DC operate as before. The first digit dialled operates relay DAD and then DBD, relay DBD at armature dbd opens the circuit of DAD which releases; the magnet CDM does not energize as before, but steps the wipers -137 when the 1.50

second digit is received. The single impulse comprising the second digit energizes magnet CDM and the wipers 130-137 are stepped to the second'set of bank contacts. Moreover wiper 122 is also resting on the second bank contact as this is the particular calling junction, and if the banks of wipers 122 and 131 are directly multipled as shown a circuit will be closed for relay DC which, in the example where a satellite subscriber calls a number served by the same otfice, will remain operated throughout the period during which the register translator is used. The straight multiple shown in the drawings involves the assumption that each satellite exchange has access to the tandem exchange over one junction only though this is of course not essential. When switch R rotates and connects the register controller with that junction and when magnet CDM is so operated by the first two digits dialled by the satellite subscriber that wipers 122 and 131 complete the holding circuit of relay DC, it follows that the calling party.

has dialled a number served by his local oifice and that the circuit conditions must be so arranged that all pulses sent out from the register translator are transmitted back over the junction to the calling equipment. Moreover the routing digits normally required to be sent out by the register translator are not required for the particular call being dealt with and armatures c105 and (108 prepare circuits to absorb these routing digits and allow numerical digits only to be sent. The manner in which this is accomplished will now be described.

When the sending operation is started, the first or metering digit will be sent out over the junction to operate the metering switch in a similar manner to that already described except that this digit will be 1, thereby advancing the minor switch wipers one step and setting them on the 1st zone metering contacts. Moreover, as relay DC does not release in this instance after the first digit has been sent out subsequent impulses will also be transmitted over the junction.

In the particular example shown, where the called partys number is 2129, and the normal translation is 19 for the ofiice code digits 21, the first digit 1 having been sent out, it follows that in normal circumstances the second digit 9 would be transmitted; in the present case where the call originated in office 21, however, the trunking digit 9 is not needed and is absorbed in the following rnanner. After the sending of the first digit, the stop relay DSZ operates to suspend the sending of impulses and magnet SSDM advances its wipers 138 and 139 to the home contacts; relay DSA now de-energizes and steps wipers 140--144 of the output control switch to the third set of contacts. Relay DSZ remains energized via normal position of armature dsa2, armature dc5, second bank contact and wiper 141 to earth via bank and wiper 147 and armature (11213. The magnet CSDM also energizes via its interrupter springs in parallel with relay DSZ and advances its wipers to the next set of contacts; this sequence of operations continues until wiper 141 reaches bank contact number 6 associated with the first numerical digit and fails to find earth whereupon the circuits of magnet CSDM and relay DSZ are opened.

Relay DSZ is de-energized and opens the circult of the vibrator DV and the impulses of the first numerical digit 2 are sent out over the junction to relay DA which vibrates its armature in response to the impulses and connects earth via normal position of armature dal, normal position of armature cbl, wiper 163 and bank, normal positions of armatures ad5, M4, 0013, bd5 and 11113 to the lower winding of relay AD which, being of the two-step type, operate; its adl armature only. When armature dal returns to its operated position at the end of the first impulse, relay AD energizes fully and prepares the circuit of relay BD which will be energized by the second impulse. Moreover, relay C, which energized initially in parallel with relay AD and remained energized during the two impulses of the digit, now de-energizes and switches the impulse circuit over to magnet LDM via armature bdl; relay TD also operates during impulsing.

The next series of impulses for the second numerical digit 9 will be extended via armatures dal and cbl, wiper 163 and bank, normal position of armature ad5, armature bd4, normal positions of armatures 02, Q6, h5, and 01 to magnet LDM, while will advance its associated wipers nine steps. Relay E energizes in parallel with magnet LDM and relay TD is again energized and at armature tdl closes a point in the circuit of relay G. Moreover armature e3 closes the circuit of relay S which energizes and at armature .94 close: a further point in the circuit of relay G which is now extended to wiper 160. Relays TD and E are slow to de-energize and if, during the period that they remain operated after the wipers come to rest, relay G receives earth from wiper 160 indicating that the called partys line is engaged it will energize and provide its own locking cir cuit via armature g2 and earth at armature k6 when relay TD de-energizes and restores its armature tdl. When relay E de-energizes busy tone from conductor 177 via armatures 64 and 95 will be connected to the calling partys line, armature e2 will cause relay KA to deenergize and thereby release the junction for service to other callers. If the called subscribers line is free, wiper 160 will find battery and when relay TD de-energizes after the second digit, relay H will be energized over the following circuit: earth, armature k6, armature g1, lower winding of relay H, armature tdl, armature s4, armature ch5, wiper 160 and bank to battery over conductor via called partys L and CO relays. Relay H will energize over its lower winding and at armature h3 complete a locking circuit for itself, and at armatures hl and 112 will connect ringing current through the winding of relay F to the called partys line and the bell will ring; armature h6 will open the circuit to relay KA which will de-energize and free the junction equipment.

When the called party removes his receiver, direct current will flow through the winding of relay F over the loop and allow relay F to energize. Armature f3 closes a locking circuit for relay F; armatures f1 and f2 complete the talking circuits between calling and called subscribers, while armature f4 opens the circuit of relay M which de-energizes and completes the metering circuit as previously described.

A further case will now be described in which a call originating in a second satellite exchange is rout-ed to the satellite exchange shown in the drawings. In this case the bank contacts shown at the end of conductors 25-27 will be seized by wipers of a 1st code selector switch which will extend earth to the bank contact and conductor 25 and thence via armature sb9 to relay SW which will energize and at armatures $201 and sw2 switch conductors 26 and 27 through to conductors 20 and 21 and the junction. The loop in the 1st code selector will now energize relay BA whereupon armature bal will close the circuit of relay BB which will energize and at armature bb3 extend earth over conductor 22 to the relevant bank contact of switch CDM (wiper 6) thereby preventing the junction from being taken into use for an outgoing call. Armature bbl prepares the impulsing circuit, armature bb2 opens the homing circuit of magnet BDM, and armature bb4 prepares the circuits of relays BG and BH. Assuming that the numerical digits 0! the called party are 43, then when the impulses of the tens digit are received relay BA will vibrate its armature 4 times and relays BAD, BBD and BCD will be energized as follows: At the first impulse, armature bal will connect earth via armature bbl and normal position armatures bad3, 1222113 and 110113, to the top winding of relay BC, while a branch circuit extends via normal position armatures bbd5 and bad4 to the winding of relay BAD. Relay BC energizes fully but relay BAD operates its armature badl only until relay BA again energizes and removes the short circuit from the upper winding of BAD. Relay ,BAD now energizes completely and operates all its armatures and at armature bad5 extends the pulsing lead to relay BBD. The next (2) pulse will operate relay BBD which at armature bbd2 opens a point in the circuit of relay BAD which de-energizes, and at armature bbd5 switches the pulsing lead over to relay BCD which energizes with the. next (3) impulse and at armature bcdfi opens a link in the circuit of relay BB D which de-energizes; armature bcd5 also prepares the holding circuit'ior relay BAD which is energized by thenext (4) impulse. Armature bcd6 closes a circuit over the first bank contact and wiper 115 for magnet BDM in series with its interrupter springs whereupon wipers 112115 are stepped to the second set of bank contacts where armature bcd4 has. closed a further link in the magnet driving circuit, and the wipers are advanced to the eleventh set of contacts. Armature bad4 now maintains the driving circuit and the wipers reach the 21st set 01 contacts where wiper 15 fails to find earth. Relay BC which was energized throughout the first train of impulses remains energized in parallel with magnet BDM during the automatic rotation of the wipers and de-energizes when the driving circuit is opened.

The impulses for the units digit (3) are given via earth at armature bal, armature bbl, armature bad3, normal position of armatures bcl, bh'l, M2 and 1202 to magnet BDM which advances its wipers three further steps. Moreover relay BE energizes in parallel with magnet BDM and .at armature be4 closes the circuit of relay BS which energizes; armature be2 closes a point in the circuit of relay BG which is now extended via armature bsl to wiper 114.

If the called partys line is engaged, earth on the bank contact associated with his line will extend over wiper 114 to relay BG which will energize. Then, when relay BE releases at the end of its slow release period, busy tone over conductor 1'78 will be extended via armatures be3 and bg i to the calling partys line.

If the called partys line is disengaged, wiper 114 will extend battery to the winding of relay BH when relay BE releases and relay BH will close its own locking circuit at armature bhl to earth at armature Z253. Armature D723 and bh will now extend ringing current via the winding of relay BF and ringing return battery to the called subscriber's bell which will ring.

When the called party answers, direct current will fiow through the winding 01 relay BF which will energize and at armature hi3 close its own locking circuit, while at armatures bfl and M2 it will complete the talking circuits between the calling and called parties.

It should be mentioned that though in the example given, the number of impulses transmitted to effect the setting of the 1st code selector was less than ten, the wiring of the bank of wiper 138 permits the transmission of any number up to 35 since the sender switch is only provided with one normal position.

We claim:

1. In a multi-exchange telephone system; a plurality of exchanges, register senders located in one of said exchanges, means including trunk lines interconnecting said exchanges whereby any one of said register senders may be taken into use from any exchange, automatic switches in each of said exchanges arranged to respond to impulses to set up desired connections, and means for operating a register sender to transmit impulses to automatic switches in the same exchange and to transmit impulses to the automatic switches in any other exchange independent of any automatic switches in the same exchange with said register senders.

2. In a multi-exchange telephone system, a plurality of exchanges, directively controlled automatic switches in each of said exchanges arranged to set up local and interexchange connections between subscribers lines, means including interexchange trunk lines whereby, upon the initiation of a call in any one of said exchanges, one of said register senders is taken into use, said register sender being arranged to be set in accordance with impulses received from the line over I-'.'

which it is taken into use and to retransmit impulses to position the necessary automatic switches to complete the desired connection, as indicated by its setting, and means whereby impulses are transmitted from any register sender taken into use to any exchange other than the one in which the register senders are located over a circuit path excluding the directively controlled automatic switches in the exchange in which the one of said exchanges for setting up a connection I over an interexchange trunk line to one of said register senders, means for transmitting impulses to said register sender over said connection, and means in said register sender for transmitting impulses in the opposite direction over said con- I nection to the exchange in which the call originated, and means in the originating exchange responsive to said impulses to set up the desired connection.

4. In a multi-exchange telephone system, automatic switches in each exchange, register senders in one exchange, means for sending impulses to said register senders from calling lines in any exchange, and means in said register senders responsive to impulses indicating a desired con- 1'..--

Jill

the exchange containing the register senders.

5. In a multi-exchange telephone system, register senders located in one of said exchanges and arranged to control the automatic establishment of talking connections, automatic switching apparatus responsive to a call in any one of said exchanges for setting iipa connection to any one of said register senders, the number of switches involved in a connection set up from a calling line to a register sender being independent of whether the calling line terminates in the same exchange with the register senders or in another exchange.

6. In a multi-exchange telephone system, a group of local switches in each exchange, a group of tandem switches in one exchange, and means responsive to a call originating on a line of any one ofsaid exchanges for connecting a local switch to said line and for connecting a tandem switch with the local switch.

7. In a multi-exchange telephone system, a group of local switches in each exchange, a group of tandem switches in one exchange, means responsive to a call originating on a line of any one of said exchanges for connecting a local switch to said line and for connecting a tandem switch with the locaLswitch, register senders associated with said tandem switches, and means responsive to any tandem switch being taken into use for connecting any one of said register senders therewith.

8. In a multi-exchange telephone system, a group of local switches-in each exchange, a group of tandem switches in one'exchange, means responsive'to a call originating on a line of any one of said exchanges for connecting a local switch to said line and for connecting a tandem switch with the local switch, registersenders associated with said tandem switches, means responsive to any tandem switch being-taken into use for connecting any one of said register senders there,- with, and means in any register sender taken for use for sending impulses over one circuit path to operate the connected tandem switch and for sending impulses over anothercircuit path to operate the connected local switch.

9. In a multi-exchange automatic telephone system, register senders located in one of the exchanges of the system and arranged to respond to impulses transmitted thereto from calling automatic lines and to retransmit impulses to the automatic switching apparatus to bring about the setting up of desired connections, said register senders being arranged to form a separate unit and to be connected to the automatic switches in the exchange in which they are located in the same manner in which they are connected to the automatic switches in the other exchanges.

10. In a multi-exchange automatic telephone system, groups of link circuits in one of said exchanges individual to said exchanges, respectively, control devices in the said one exchange common to all of said exchanges, said control devices being associated with calling lines of said exchanges through the intermediation of said link circuits, and means depending upon the exchange group in which a link circuit with which a control device is connected is located for variably controlling the connected control device means responsive to the initiation of a call in any exchange to cause one of the corresponding link circuits to associate a control device with the calling line in the calling exchangameans on the said calling line to set up on said'control device a registration of the number of the wanted line, and means automatically efiective and dependent upon the group in which the instant controlling link circuit is locatedfor setting up in said control device a registration of the exchange containing the calling line.

12. In a telephone system, calling lines arranged in separate groups, linkcircuits indivldual to each group, control devices common to all groups for controlling the automatic establishment of connections, means responsive to the initiation of a call for one of said lines to cause one of the corresponding link circuits to associate a control device with said line, said means including a finder switch individual to said controlling device and having access to all of said link circuits, and means dependent upon the set position of said finder switch for setting up in said control device a registration of the group in which the calling line is located.

13. In an automatic telephone system employing register controllers, means responsive to the initiation of a call for connecting a register controller with the corresponding line, saidmeans including a finder switch individual to said register controller, means on the calling line to set up on said register controller a registration of the number of the wanted line, and means dependent upon the position in which said finder switch is set in connecting the register controller with the calling line for modifying the operation of the register controller.

14. In a telephone system employing register controllers, a single-level switch arranged to have access to a plurality of groups of lines leading in different directions, means for transmitting impulses from a register controller to said switch, and means insaid switch directly responsive to said impulses for. moving the switch into association with the first line in the corresponding group. a

15. In a telephone system as claimed in claim 1, means whereby the impulses transmitted to automatic switches in the same exchange are .2

transmitted over a loop circuit and whereby the impulses transmitted to another exchange are transmitted over one talking conductor only.

-16. In a telephone system as claimed in claim 1, first numerical switches located in the exchange including said register senders, andistered wanted group for modifying the operation of the register controller.

1 8. In a telephone system as claimed in claim 12, means for setting up in said register controller a registration of the group containing the wanted line, two impulse circuits outgoing from said register controller, and means depending jointly upon the registered indication of the calling group and the registered indication of the detions originating in any one or said exchanges,

telephone number for positioning the wipers of said switch on the first set of contacts in a desired group, said switch having two test wipers and two corresponding banks of test contacts, one of said test wipers having access to all test conductors of alllines, the other test wiper having access to all of the test conductors; of all lines except the Y last line in each group.

20. In a register sender for use in a multiexchange telephone system,- a single-level ex-- change-register switch having its bank contacts arranged in groups corresponding to the group- 2 ing of the exchanges, means including a group of counting relays responsive to a series-of impulses indicating the desired exchange group for advancing the exchange register switch into association with the contactgroup corresponding ,to the desired exchange groupI and means responsive to impulses corresponding to the desired exchange within the desired group for again advancing said exchange register switch until it comes into association with the contact assigned to the desired exchange.

21. In a telephone system, a single-level automatic switch having access to lines arranged in groups, there being a separate two-digit combination assigned to each of said lines, means responsive to impulses representing the first digit of a two-digit combination and including a set of impulse counting relays for advancing said switch into association with the corresponding group of lines, means responsive to the impulses representing the second digit of the combination for advancing said switch into association with the line to which the two-digit combination is assigned and means included in the first-named means for preventing the first-mentioned advance of said wipers unless the first digit is represented by more than two impulses.

- ter sender, means responsive to a call originating on 'a telephone line for connecting said line with both of said automatic switches and with said register sender, means in said register sender controlled over the calling line for registering digits in desired telephone numbers, sending means in said register sender operable under the control of the registering means for re-transmitting digit impulses indicative of the desired connection, and means dependent upon the setting of said registering apparatus for determining to which of said a.'.tomatic switches the digit impulses are to be transmitted.

23. In a telephone system, two automatic switches, a register sender, means responsive to 55 the initiation of a call on a subscribers line for associating said automatic switches and said register sender therewith, said register sender being arranged to register digits transmitted thereto from the calling line and to control either when the registering apparatus is set in accordance with another digit combination to cause said register sender to directively control the second of said automatic switches to extend the calling line.

24. In a telephone system, two directively conolled automatic switches, means responsive to a call being initiated on a subscribers line for associating both of said switches with the line, means controlled over said line for operating either of said switches to extend a connection from the line independent of the other switch, and means responsive to one of said switches being completely positioned for disassociating the other switch from the line.

25. In a telephone system, two automatic switches, each of said switches being available for the common use of a plurality of subscribers lines, means responsive to a call being initiated on any one of said lines for taking both of said switches for use, means controlled over the calling line for directively operating either of said switches to the exclusion or the other to extend a connection from the calling line, and means,

of the register senders in the second exchange with said line, means controlled over the calling line for setting up in said register sender a registration of the desired connection, and means controlled by said register sender in accordance with the registration set up for directively op- :11"

erating the associated switch in either exchange to extend the connection.

27. In 'a multi-exchange telephone system, two

exchanges, automatic switches in both exchanges,\

register senders in the second exchange, means responsive to the initiation of a call. on a line of I the first exchange for extending a connection from such line to a register sender in the second exchange, means in the said register sender for registering the desired number under 1' the control of the calling line in the first exchange, and means controlled by said register in the first exchange or an automatic switch in.

the second exchange to extend the connection, depending upon the location of the called line as indicated by the registered number.

28. In a multi-exchange telephone system, register senders in a first. exchange arranged to control the extension of calls originated on lines entering said exchange, a trunk line interconnecting the first exchange with a second exchange, means responsive to the initiation oi a call on a line in the second exchange for extending a connection from said line over said inter-exchange trunk line to a register sender in the first exchange, automatic switching apparatus in the second exchange arranged to be directively operated to extend the connection if a1..."

a line of the second exchange is being called, and means controlled by said register sender for operating one of said automatic switches in the second exchange over said trunk line to extend the connection.

29. In a multi-exchange telephone system, two exchanges, register senders located in the second exchange, an inter-exchange trunk line interconnecting said exchanges, means responsive to a call originated on a line 01' the first exchange for extending a connection over said inter-exchange trunk line to a register sender in the second exchange, registering apparatus in the register sender for registering the digits of desired numbers, means for transmitting the digits of the desired number over said interexchange trunk line from the calling line to position said registering apparatus, automatic switching apparatus in the first exchange, and means in said register sender for transmitting digits back over said inter-exchange trunk line from the second exchange to the first to operate said automatic switching apparatus to extend a connection from the calling line.

30. In a multi-exchange telephone system, two exchanges, an inter-exchange trunk line extending between said exchanges, automatic switching apparatus located in said exchanges and arranged to extend connections from calling lines, register senders in the second exchange, means responsive to a call being initiated on a line of the first exchange for extending a connection from the line over said interexchange trunk line to a register sender in the second exchange, means effective when this connection is set up for establishing two impulse channels over said trunk line, means for trans mitting impulses over one of said channels from the calling line to position the registering apparatus of said register sender, and means for transmitting impulses back from said register sender over the other of said channels to position automatic switching apparatus in the first exchange to extend a connection from said line.

31. In a multi-exchange telephone system, two

exchanges inter-connected by a trunk line, reg

ister senders in the second exchange, means responsive to a call originating on a line of, the first exchange for extending a connection by way of said inter-exchange trunk line to a register sender in the second exchange, automatic switching apparatus in both exchanges, means for establishing a switch-control circuit between the automatic switching apparatus of the first exchange and said registersender and for establishing a separate switch-control circuit between automatic switching apparatus in the second exchange and said register sender, and means in said register sender depending upon the number registered for determining over which of said control circuits the control shall be exercised.

32. In a multi-exchange telephone system, two exchanges inter-connected by a trunk line, register senders in the second exchange, means responsive to a call originating on a line of the first exchange for extending a connection by way of said inter-exchange trunk line to a register sender in the second exchange, automatic switching apparatus in both exchanges, means for establishing a switch-control circuit between the automatic switching apparatus of the first exchange and said register sender and for establishing a separate switch-control circuit between automatic switching apparatus in the second exchange and said register sender, and means for ister senders ih the second exchange, means responsive to a call originating on a line of the first exchange for extending a connection by way of said inter-exchange trunk line to a register sender in the second exchange, automatic switching apparatus in both exchanges, means for establishing a switch-control circuit between the automatic switching apparatus 01' the first exchange and said register sender and for establishing a separate switch-control circuit between automatic switching apparatus in the second exchange and said register sender, means always effective for determining over which impulse circuit the remaining series of impulses are to be transmitted, depending upon the location of the called line as indicated by the registered number.

34. In combination, a register sender, means for taking said register sender for use and for setting up a number on the registering apparatus thereof, two separate impulse circuits outgoing from said register sender and means for preparing them for impulses to be transmitted thereover, a sender in said register sender operable to transmit a plurality of series of impulses under the control of the registering apparatus, and means for causing one of said series of impulses to be transmitted over one of saidcircuits and for causing the remaining ones of said series of impulses to be transmitted over the other of said circuits.

35. In combination, a register sender operable to transmit impulses to two separate places, means for taking said register sender into use and for starting it to transmit impulses, a relay and means for operating it to predetermine that the first impulses will be transmitted to the first of said places instead of the other, and means effective following the transmission of the first part of said impulses for restoring said relay so as to cause the remaining impulses to be transmitted to the second of said places instead of to the first.

36. In combination, a register sender operable to transmit impulses to two separate places, means for taking said register sender into use and for starting it to transmit impulses, a relay and 1 means for operating it to predetermine that the first impulses will be transmitted to the first of said places instead of the other, means efiective following the transmission of the first part of said impulses for restoring said relay so as to cause the remaining impulses to be transmitted to the second of said places instead of to the first, and means effective depending upon the value of the impulses which are to be transmitted for maintaining said relay operated continuously until all of said impulses have been transmitted, whereby all of the impulses are transmitted to the first place and none of them to the second place.

37. In an automatic telephone system, a plurality of groups of automatic telephone lines terminating in a plurality of exchanges, respectively, a group of register senders common to all of said groups of lines and arranged to be controlled over any line to register the digits of desired l telephone numbers and to control the setting of the automatic switches in accordance with the registered digits, each of said register senders being arranged to operate in either of two distinct manners, and means effective when a register sender is in use and depending jointly upon the group in which the line with which it is being used is located and the number transmitted to the registering apparatus of the register sender from said line for determining in which 

